Constant speed hydraulic system



Sept. 9, 1941. .1. Pl JOHNSON CONSTANT SPEED HYDRAULIC SYSTEM Filed Feb. 20, 1939 2 Sheets-Sheet 1 I NVENTOR. .fivmss few/v50 m4 1. M

Sept. 9, 1941. J. P. JOHNSON 2,255,539

CONSTANT SPEED HYDRAULIC SYSTEM Filed Feb; 20, 1959 2 Sheets-Sheet 2 Patented Sept. 9, 1941 CONSTANT SPEED HYDRAULIC SYSTEM JamesP. Johnson, Shaker Heights, Ohio. assignor, by mesne assignments, to Pump Engineering Service Corporation, Cleveland, Ohio, a corporation of Ohio Application February 20, 1939, Serial No. 257,549

2 Claims.

This invention relates to improvements in the driving of generators, pumps, etc., and particularly as employed on aircraftalthough not so restricted. 1 1

At the present time it is customary to .drive generators, oil pumps, vacuum'pumps and the like by directly connecting these accessories with the engine or with the well known gear box-having a plurality of these drives with which the accessories are directly connected.' In both cases, however, the accessories are overloaded due to the higher speed at which the engine must operate particularly in drives and take-offs which has resulted in much trouble fromthis source.

A still further method of mounting these accessories has been the use of auxiliary engines,

due to the fact that so many accessories are now mounted upon the engine, but the use of these auxiliary engines involves expense, adds to the load, and lacks efficiency. 1

It is therefore, one of the objects of the present invention to provide a mounting for these accessories entirely remote from the engine thereby permitting installation at the most desirable places so as to distribute the weight to the best advantage.

Another object of the present invention is to provide for hydraulic actuation of the accessories. Another object of the present invention is to drive the accessories at approximatelya predetermined speed thus eliminating the objectionable overdrive now present.

Another object of the present invention resides in the provision of individual hydraulic motors for each accessory thereby driving each accessory at the most effective speed. v A still further object of the present invention is to effect flow of the actuating medium by means of a hydraulic pump'drivingly connected to the engine and to control the quantity of medium introduced into the inlet side of the pump whereby variations in the speed of the engine will have little influence upon theactuating medium.

Astill further object of the present invention is the use of a manifold on which the accessories are mountable and which can be mounted upon the plane at the most advantageous location whereby the weight is properly distributed and installation difliculties overcome.

A still further object of the present invention is to provide a system and apparatus which is simple in construction and efficient in operation, and relatively inexpensive to manufacture.

tion consists in the construction and combination of elements hereinafter described and'claimed.

Referring to the drawings, Figure 1 Ba diagrammatic plan view of the apparatus embodying the presentinvention.

Figure 2 is an end elevational view-at the manifold end of the apparatus with the manifold shown in section to more clearly illustrate the.

structure and taken on line 2--2 of Figure 1.

Figure 3 is a fragmentary sectional view 01 a modified form of control for the inlet side of the Figure 4 is a fragmentary sectional'view of a further modified form of controlembodying automatic operation.

In the drawings, particularly referring to Figures 1 and 2, I have shown an apparatus embodying the present invention, the apparatus being of simplified form so that the-invention may be more readily understood. A high pressure oil pump ll, preferably of the well known gear type,

has an inlet opening ii communicating with the inlet side of the pump gears and an-outlet opening l2 communicating with the .outletside of the With the objects above indicated and other pump gears in a well known manner, whereby upon rotation of the gears in-the proper direction fluid will be drawn into-the inletopening l l and discharged under pressure from the outlet opening. One of the pump gears has a shaft which projects outwardly-beyond the housing and is formed with an extension l3 directly. connected with the engine or other source of driving power by which the pump gearsare rotated. The oil pump in may be mounted in anyof the well known'manners but, in the present instance, such a mounting is not disclosed inasmuchas it forms no part of the invention. I v

The'inlet opening Ii is interiorly"screwthreaded to receive the exteriorly screwthreadedjend' of a T connection I, the connection being providedwith a laterally disposed interiorly.screwthreadcd opening l5 into which the screwthreaded end of.

a pipe 16 is securely fitted. The other end of the pipe (6 is sealingly connected with the lower portion of an oil supply tank II in a manner to permit the flow of fluid preferably oil from the tank to the inlet side of the oil pump through the pipe 16. A pipe [8 has its lower end connected with the top of the tank H to provide a means'by which oil may be introducedinto the tank and further, to function, as a vent, thus placing the inside of the tank in communication with the atmosphere.

The outlet opening [2 of the oil pump is, likeoblects hereinafter explained in view, my invenwise, interiorly screwthreaded to receive one end of the gears.

known in connection with hydraulic motors and of a pipe l9 while the opposite end of the pipe is connected to a manifold 20 in a manner to be later described. The manifold 20, in this in stance, comprises a casting, of rectangular shape in plan view, having a longitudinally extending passageway 2|, the opposite ends of which are interiorly screwthreaded. The manifold is further provided with a longitudinally extending the desired manner. In the present instance, as

shown in Figures 1 and 2, the passageway 2| is the inlet passageway and one end is adapted for connection with the end of the pipe I9. The opposite end of the passageway 2| is closed by a removable plug 23. The passageway 22 in this instance'is the outlet or exhaust passageway, and it is connected at one end with a pipe 24 which has its opposite end connected to the upper portion of the tank H. The opposite end of the passageway 22 is closed-by a removable plug 25 of the type similar to the plug 23. The upper surface of the manifold 20 is provided with mounting pads 26 which are in longitudinal alignment but spaced apart relatively, there being disclosed in Figure 1 three of such mounting pads, but it should be understood that any number may be provided depending upon the number of accessories to be mounted on the manifold. The manifold 20 is further provided with a plurality of openings 21 affording communication between the inlet passageway 2| and one side of the mounting pad 26, and further provided with a plurality of openings 28 affording communication between the outlet passageway 22 and the opposite side of the mounting pad 26.

On each mounting pad 26 there is mounted a hydraulic motor 29, preferably of the well known gear type. Each of the hydraulic motors has an attaching flange 30 disposed upon one of the mounting pads 26 and secured by bolts 3|. Each hydraulic motor is further provided with a passageway 32 communicating at its lower end with the adjacent opening 21 and at its upper end with the inlet side of the gears. A similar passageway 33 is provided on the opposite side of the hydraulic motor and has its lower end communicating with the adjacent opening 28 and its opposite end communicating with the outlet side All of this construction is well for that reason it is not believed necessary to illustrate the structure details of the motors. It is suffice-to say that fiuidunder pressure is introduced into the inlet passageway 32 where it causes the gears to berotated and the spent me- 7 dium to be discharged through the outlet passageway 33, the rotation of the gears effecting rotation of a shaft, not shown, which projects outwardlyof the hydraulic motor housing and is .drivingly connected with the accessories which are to be operated thereby. In the present instance, an oil pump 34 is connected with one hydraulic motor, a generator 35 is connected with through the inlet opening due to the suction,

created and discharges the fluid under pressure from the outlet opening |2 where it flows through the pipe l9 and into the inlet passageway 2| of the manifold 20. 'From here the oil passes through the openings 21 upwardly through the inlet passageways 32 into the inlet side ofthe hydraulic motors. The pressure is such as to cause rotation of the gears which in turn operates the respective accessories mounted uponeach motor. The spent oil carried around 'by the motor gears is discharged through the outlet passageways 33 where it flows through the openings 23 and into the outlet passageway 22 of I the manifold. From here the-oil flows through the pipe 24 and back to the supply tank H where it is used over andover again.

With this arrangement, however, variations in the engine speed would create variations in the pressure of the oil which would likewise result in variations in the speeds of the hydraulic canonly take in a limited quantity of oil and thereby discharge a limited quantity irrespective of engine speed variations. This plug is mounted so as to be removable and for this reason plugs with different sizes of orifices may be substituted where diiferent conditions exist. The end ,of the T-member I4 is closed by a screwthreaded plug 39 and a gasket 40 aifords a sealed joint.

Withjthis arrangement, it is further possible to employ hydraulic motors of different displacements and, therefore, to enable the selection of the proper capacity hydraulic motor for driving the particular accessory and thereby provide diiferent driving speeds despite the fact that the actuatin pressure of the medium remains constant. f

In Figure 3, a modified form for varying the effective size of the inlet opening to the oil pump is shown. In this case the T-.member I4 is provided with a plug 4| which is disposed on the inside of the member in abutment with a shoulder 42. The plug 4| has a tapered opening 43 extending axially therethrough with the widest part of the opening away from the inlet side of the pump and the plug 39' is interiorly screwthreaded. A tapered valve head 44 is disposed within the opening 43 and has an exteriorly screwthreaded portion 45 rotatably mounted within the screwthreaded opening in the plug 39. A stem 46 projects centrally through a tubular extension 41 on the plug 39' and has an adjusting-- wheel 48 secured to its outer end by means of which the valve head 44 is axially ad justed with reference to the opening 43 in the plug 4|. By adjusting the valve 44 with respect to the opening 43, it is possible to vary the quantity of oil introduced into the inlet side of the oil pump. A packing nut 49 is screwthreadedly disposed in the outer end of extension 41 and compresses a packing 50 so as to afford a fluid tight joint.

In Figure 4, a still further modified form of control valve is illustrated. In this instance, the T-member H has a restricted opening 5| adjacent the inlet side of the oil pump. The inlet 1 pipe I6 is connected in the manner shown in Figure 1 and affords communication between the oil supply tank and the inlet side of the oil pump.

The opposite end of the T-member I4 is closed by a member 52 having a laterally extending flange 53 by which the member 52 is detachably connected. The member 52 has a tubular extension 54 which projects axially outwardly therefrom and a tapered extension 55 which projects 1 inwardly therefrom and is provided with an axial opening of smaller size than the inside of the extension 54 so as to provide an abutment or shoulder 55. A valve member has a tapered valve head 51 which is disposed within the opening and a stem 58 which projects outwardly therefrom and is slidably disposed within the opening in the extension 55. A flexible bellows 59 is disposed within the member l4 and has one end sealingly connected to the valve head and its other end' sealingly connected to the member 52, in such a manner as not to interfere with the communicashoulder 55. In this manner, the valve head is normally urged away from the opening 5| and is moved in the opposite direction by the suction I at the inlet opening of the oil pump. The tension of'the'spring 52 may be adjusted by movement of the collar 5| and a simple means resides in providing a sleeve 63 which is rotatably disposed on the inside of-the tubular extension 54 projecting inwardly at least as far as the end of the rod is threaded; The sleeve is, likewise, disposed over the collar 5| and has a slot 54 to slidably'receive a lug 55 formed on the collar An extension 55 projects outwardly beyond the sleeve' and affords a means by w ch the sleeve may be rotated which in turn varies the position of the collar 5| upon the screwthreaded end of the stem. The sleeve 55 is provided with a laterally extending flange 51 which abuts the end of the tubular extension 54, and a nut 58 is removably connected to the outer end of the tu bular extension. When the nut 55 is secured in place the flange 51 isrigidly clamped so as to maintain the spring in its adjusted position.

While I have described the preferred embodiment of the invention it is to'be understood that I am not to be limited thereto inasmuch as changes and modifications may be resorted to without departing from the spirit of the invention as defined in the appended claims.

What is claimed is: 1. In a fluid pressure delivery and discharge manifold assembly, an elongated manifold member having formed therein a pair of longitudinally extending separated passages having threaded terminal portions, a first one of said passages having one end thereof closed by a threaded closure plug and the other end thereof adapted to be connected with the threaded terminal of a conduit leading from a source of fluid under pressure, said other passage having its terminal located adjacent said plug being adapted to receive a complementary terminal portion of a return conduit leading back to said fluid pressure source, and a second threaded plug closing the other end of said last named passage, a plurality of pairs of generally aligned ports formed in the upper surface of said casting, a first port of each of said pair of ports being in communication with said flrst passage and the remaining port of each pair of ports being in communication with said other passage, a'plurality of separate fluid motors each formed with an inlet opening and a discharge opening, and separate adaptor means for mounting said motors on said manifold member eflective to place said motor inlets-in communication with said first ports and the motor outlets in communication with said remaining ports, and means for readily assembling in attached relation said adaptors, motors, and manifold member. v I

2. In a fluid delivery and discharge manifold assembly, an elongated casting of generally rectangular cross-section, said casting being formed with a pair of generally parallel separated longi tudinally passages extending from one end to the other thereof and having threaded terminal portions, a first one of said passages having one end thereof closed by a complementary threaded closure plug and the other end thereof adapted to be connected with the threaded terminal portion of a conduit leading from a source of fluid pressure, said other passage having the portion thereof adjacent the said plug adapted to receive the threaded terminal portion of a return conduit leading back to said fluid pressure source, and a second threaded plug received in the other end of said last named passage, a plurality of pairs of generally aligned ports formed in the upper portion of said casting, and separate adaptor means associated with each pair of said ports efl'ective to support a fluid motor and to place the inlet of each oi said motors in communication with a 'flrst .one of said ports and the discharge side of said fluid motors with said second one of said ports. and means for readily attaching and detaching said adaptor means to said castand said motors to said adaptors.

. JAMES P. JOHNSON. 

